What does it mean to say that two variables are positively? associated?
There is a linear relationship between the? variables, and whenever the value of one variable? increases, the value of the other variable increases.
True or? false: Correlation implies causation.
False
if the relationship is linear do the variables have a positive or negative? association?
The relationship is not linear.
why correlations should always be reported with scatter diagrams?
The scatter diagram is needed to see if the correlation coefficient is being affected by the presence of outliers.
What does it mean to say that the linear correlation coefficient between two variables equals? 1? What would the scatter diagram look? like?
en the linear correlation coefficient is? 1, there is a perfect positive linear relation between the two variables. The scatter diagram would contain points that all lie on a line with a positive slope.
What does it mean if r=?0?
no linear relationship exists between the variables.
true or? false?The? least-squares regression line always travels through the point (x,y)
true
What is a? residual? What does it mean when a residual is? positive?
A residual is the difference between an observed value of the response variable y and the predicted value of y. If it is? positive, then the observed value is greater than the predicted value.
The coefficient of determination,Upper R squared
measures the proportion of total variation in the response variable that is explained by the least squares regression line.
Total deviation equals?
unexplained deviation plus explained deviation
residual plot
is a scatter diagram with the residuals on the vertical axis and the explanatory variable on the horizontal axis.
following interpretations of the mean
As the number of experiments? increases, the mean of the observations will approach the mean of the random variable.
true or false. In the binomial probability distribution? function, nCx represents the number of ways of obtaining x successes in n trials.
True